1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to encoding and decoding of an audio signal, and more particularly, to encoding and decoding an audio signal which apply an effective coding method for each band by dividing the audio signal into a plurality of bands.
2. Description of the Related Art
An encoding method of an audio signal can be classified into a parametric coding method and a time-frequency coding method. In the case of the parametric coding method, an encoding efficiency is high when a bit rate of data is low. In other words, the encoding efficiency of the parametric coding method decreases as the bit rate increases. The time-frequency coding method is more effective than the parametric coding method when sound quality of the audio signal is high, that is, the bit rate is high. However, the time-frequency coding method is ineffective when the bit rate is low, since information on all frequency indices should be transmitted.
Thus, in order to improve the encoding efficiency, a related art method in which only either the parametric coding method or the time-frequency coding method is applied, has to be improved.